Re: [ccp4bb] Death of Rmerge

2012-06-01 Thread Ian Tickle
On 1 June 2012 03:22, Edward A. Berry ber...@upstate.edu wrote: Leo will probably answer better than I can, but I would say I/SigI counts only the present reflection, so eliminating noise by anisotropic truncation should improve it, raising the average I/SigI in the last shell. We always

Re: [ccp4bb] Death of Rmerge

2012-06-01 Thread aaleshin
Please excuse my ignorance, but I cannot understand why Rmerge is unreliable for estimation of the resolution? I mean, from a theoretical point of view, 1/sigma is indeed a better criterion, but it is not obvious from a practical point of view. 1/sigma depends on a method for sigma estimation,

Re: [ccp4bb] Death of Rmerge

2012-06-01 Thread Phil Evans
As the K D paper points out, as the signal/noise declines at higher resolution, Rmerge goes up to infinity, so there is no sensible way to set a limiting value to determine resolution. That is not to say that Rmerge has no use: as you say it's a reasonably good metric to plot against image

Re: [ccp4bb] Death of Rmerge

2012-06-01 Thread Ed Pozharski
http://www.nature.com/nsmb/journal/v4/n4/abs/nsb0497-269.html http://scripts.iucr.org/cgi-bin/paper?S0021889800018227 Just collect 360 sweep instead of 180 on a non-decaying crystal and see Rmerge go up due to increase in multiplicity (and enough with redundancy term - the extra data is not

Re: [ccp4bb] Death of Rmerge

2012-06-01 Thread Jacob Keller
I don't think any data should be discarded, and I think that although we are not there yet, refinement should work directly with the images, iterating back and forth through all the various levels of data processing. As I think was pointed out by Wang, even an intensity of 0 provides information

Re: [ccp4bb] Death of Rmerge

2012-06-01 Thread Ian Tickle
Let's say you collect data (or rather indices) to 1.4 Ang but the real resolution is 2.8 Ang and you use all the data in refinement with no resolution cut-off, so there are 8 times as many data. Then your 15 mins becomes 2 hours - is that still acceptable? It's unlikely that you'll see any

Re: [ccp4bb] Death of Rmerge

2012-06-01 Thread Leonid Sazanov
Hi, as we reported in our paper in Table 1 (actually Supplementary Table 1), at the end of Scaling 2, completeness in the outer shell after aniso truncation was 54%. Whilst 96% completeness and I/sigma 0.8 is of course before aniso truncation. I/sigma after truncation would be higher, but it is

Re: [ccp4bb] Death of Rmerge

2012-06-01 Thread Jacob Keller
Let's say you collect data (or rather indices) to 1.4 Ang but the real resolution is 2.8 Ang and you use all the data in refinement with no resolution cut-off, so there are 8 times as many data.  Then your 15 mins becomes 2 hours - is that still acceptable?  It's unlikely that you'll see any

Re: [ccp4bb] Death of Rmerge

2012-05-31 Thread Jacob Keller
Meant to include the following link in the previous message: http://www.youtube.com/watch?v=9Jn8K8EA7-Q JPK On Thu, May 31, 2012 at 1:20 PM, Jacob Keller j-kell...@fsm.northwestern.edu wrote: Dear Crystallographers, in case you have not heard, it would appear that the Rmerge statistic has

Re: [ccp4bb] Death of Rmerge

2012-05-31 Thread Oganesyan, Vaheh
It wasn't doing well lately. So, it was expected. From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Jacob Keller [j-kell...@fsm.northwestern.edu] Sent: Thursday, May 31, 2012 2:20 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Death of Rmerge

Re: [ccp4bb] Death of Rmerge

2012-05-31 Thread Soisson, Stephen M
@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Death of Rmerge It wasn't doing well lately. So, it was expected. From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Jacob Keller [j-kell...@fsm.northwestern.edu] Sent: Thursday, May 31, 2012 2:20 PM To: CCP4BB

Re: [ccp4bb] Death of Rmerge

2012-05-31 Thread Edward A. Berry
Yes! I want a copy of this program RESCUT. REMARK 200 R SYM FOR SHELL(I) : 1.21700 I noticed structure 3RKO reported Rmerge in the last shell greater than 1, suggesting the police who were defending R-merge were fighting a losing battle. And this provides a lot of ammunition to

[ccp4bb] Fwd: [ccp4bb] Death of Rmerge

2012-05-31 Thread Jacob Keller
Alas, how many lines like the following from a recent Science paper (PMID: 22605777), probably reviewer-incited, could have been avoided! Here, we present three high-resolution crystal structures of the Thermus thermophilus (Tth) 70S ribosome in complex withRMF, HPF, or YfiA that were refined by

Re: [ccp4bb] Fwd: [ccp4bb] Death of Rmerge

2012-05-31 Thread Dale Tronrud
On 05/31/12 12:07, Jacob Keller wrote: Alas, how many lines like the following from a recent Science paper (PMID: 22605777), probably reviewer-incited, could have been avoided! Here, we present three high-resolution crystal structures of the Thermus thermophilus (Tth) 70S ribosome in complex

Re: [ccp4bb] Fwd: [ccp4bb] Death of Rmerge

2012-05-31 Thread Jacob Keller
Good idea, but how to get it to catch on without publishing in Science? JPK On Thu, May 31, 2012 at 4:21 PM, Dale Tronrud det...@uoxray.uoregon.edu wrote: On 05/31/12 12:07, Jacob Keller wrote: Alas, how many lines like the following from a recent Science paper (PMID: 22605777), probably

Re: [ccp4bb] Fwd: [ccp4bb] Death of Rmerge

2012-05-31 Thread Ethan Merritt
On Thursday, May 31, 2012 02:21:45 pm Dale Tronrud wrote: The resolution limit of the data set has been such an important indicator of the quality of the resulting model (rightly or wrongly) that it often is included in the title of the paper itself. Despite the fact that we now want to

Re: [ccp4bb] Fwd: [ccp4bb] Death of Rmerge

2012-05-31 Thread aaleshin
There are things you can expect to learn from a 2Å structure that you are unlikely to learn from a 5Å structure, even if equal care has been given to both experiments, so it makes sense for the title to give the potential reader an idea which of the two cases is presented. But for this

Re: [ccp4bb] Fwd: [ccp4bb] Death of Rmerge

2012-05-31 Thread Edward A. Berry
In the meantime we could follow Phoebe Rice's example and put the resolution at I/sigma=2 in REMARK 2 resolution of structure but put the actual bleeding-edge resolution we used in the reduction and refinement statistics (At least if the PDB will allow us to have different values in these three

Re: [ccp4bb] Death of Rmerge

2012-05-31 Thread Zhijie Li
: Re: [ccp4bb] Death of Rmerge Yes! I want a copy of this program RESCUT. REMARK 200 R SYM FOR SHELL(I) : 1.21700 I noticed structure 3RKO reported Rmerge in the last shell greater than 1, suggesting the police who were defending R-merge were fighting a losing battle

Re: [ccp4bb] Death of Rmerge

2012-05-31 Thread Edward A. Berry
-- From: Edward A. Berry ber...@upstate.edu Sent: Thursday, May 31, 2012 2:59 PM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Death of Rmerge Yes! I want a copy of this program RESCUT. REMARK 200 R SYM FOR SHELL (I) : 1.21700 I noticed structure